In certain types of picture film, either for still pictures or movie pictures, it frequently occurs that the film will be overly dominant in one color such as excessively red as can be found in many 16mm colored motion picture prints, for example. By the use of this variable filter device the proper amount of compensation can be introduced at the projector for correcting this condition. As in the case of excessive red in the film the degree of dominant coloration sometimes changes from time to time such as with increased red development over a period of time. Thus the filter requirements are sometimes constantly changing so that the degree of compensation must be similarly changed. The device of this invention provides a simple, inexpensive and infinitely variable means of providing the proper amount of correction.